Original Posted By: Robert Ray
TGWP is on the Encore Love channel right now. Hurry up and you can practice youlines!--------Mark - working on wingsRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Mon, 17 Aug 2009 02:52:18 -0400Subject: Pietenpol-List: wing rib jig belongs to some one don't know who
Pietenpol-List: wing rib jig belongs to some one don't know who
RE: Pietenpol-List: Sandblasting valve springs...a mistake?
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Depends on what medium you were using. If it was truly sand, you might wellhave caused a bunch of scratches on the surface that would cause stressconcentrations, leading to early failure. If the medium you used was glassbeads or walnut shells or something like that, no harm would likely be doneand it might even have a benefit in that it would act like shot-peening tocreate a layer of compression on the surface to prevent fatigue.Look at the surface of the springs with a magnifying glass or microscope andsee if you can see any scratches. Or better yet, contact Harry Fenton orTeledyne Continental Motors and get their opinions (Harry probably knowsmore about the A75 than TCM does).Jack PhillipsNX899JP-----Original Message-----
Depends on what medium you were using. If it was truly sand, you might wellhave caused a bunch of scratches on the surface that would cause stressconcentrations, leading to early failure. If the medium you used was glassbeads or walnut shells or something like that, no harm would likely be doneand it might even have a benefit in that it would act like shot-peening tocreate a layer of compression on the surface to prevent fatigue.Look at the surface of the springs with a magnifying glass or microscope andsee if you can see any scratches. Or better yet, contact Harry Fenton orTeledyne Continental Motors and get their opinions (Harry probably knowsmore about the A75 than TCM does).Jack PhillipsNX899JP-----Original Message-----
Pietenpol-List: Re: Sandblasting valve springs...a mistake?
Original Posted By: Wayne Bressler
Luckily it was only one spring set (inner & outer of #4 intake valve). Possiblyan expensive lesson. The blasting media was plain white sand. I have foundseveral articles online referencing the use of sand to improve fatigue strengthvia work hardening. I will pull out my old microscope to see what I can findon the surface, but I doubt I have the proper equipment or knowledge to makean accurate determination by looking at the surface. If I can't determine forsure, then I'll replace the spring. If I bought some new glass bead media,then re-blasted the spring, could it undo the damage potentially caused by sandby peening the surface?Now, my next question is, where do you get these springs? They are part numbers21365 & 21366. The shop that is going to hone the cylinders for me does a lotof work on these engines, maybe they have some.Thanks for the help. I'll e-mail Harry Fenton in the next day or two if I can'tfind definite information somewhere. I hate to bug him if I can find the informationby doing a little reading.Did you ever have one of those moments where you wanted to punch yourself in theface? That was me, last night.Steve RuseRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Luckily it was only one spring set (inner & outer of #4 intake valve). Possiblyan expensive lesson. The blasting media was plain white sand. I have foundseveral articles online referencing the use of sand to improve fatigue strengthvia work hardening. I will pull out my old microscope to see what I can findon the surface, but I doubt I have the proper equipment or knowledge to makean accurate determination by looking at the surface. If I can't determine forsure, then I'll replace the spring. If I bought some new glass bead media,then re-blasted the spring, could it undo the damage potentially caused by sandby peening the surface?Now, my next question is, where do you get these springs? They are part numbers21365 & 21366. The shop that is going to hone the cylinders for me does a lotof work on these engines, maybe they have some.Thanks for the help. I'll e-mail Harry Fenton in the next day or two if I can'tfind definite information somewhere. I hate to bug him if I can find the informationby doing a little reading.Did you ever have one of those moments where you wanted to punch yourself in theface? That was me, last night.Steve RuseRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Re: Pietenpol-List: skid ball
Original Posted By: "Cuy, Michael D. (GRC-RXD0)[ASRC Aerospace Corporation]"
When I did the EAA's Air Academy as a teenager, we made slip-skid balls just as Oscar described. A piece of aluminum was bent to the proper shape, and a steel ball was placed in the tube with screws/ bolts sealing the tube and holding it to the aluminum at the same time. I don't remember what we filled the tubes with, but it was probably just water.I still like Jack's idea of stripping a surplus instrument down for just a few bucks. That's pretty clever.Reminds me of the Navi-Bird somebody had in their Piet at OSH in 2001 (?). They also had a "moving map" sectional on two rollers with a hand crank, and a pair of dice inside an instrument face with a placard that said "Flying is a Gamble".Very cool.Wayne Bressler Jr.Taildraggers, Inc.taildraggersinc.com________________________________________________________________________________
When I did the EAA's Air Academy as a teenager, we made slip-skid balls just as Oscar described. A piece of aluminum was bent to the proper shape, and a steel ball was placed in the tube with screws/ bolts sealing the tube and holding it to the aluminum at the same time. I don't remember what we filled the tubes with, but it was probably just water.I still like Jack's idea of stripping a surplus instrument down for just a few bucks. That's pretty clever.Reminds me of the Navi-Bird somebody had in their Piet at OSH in 2001 (?). They also had a "moving map" sectional on two rollers with a hand crank, and a pair of dice inside an instrument face with a placard that said "Flying is a Gamble".Very cool.Wayne Bressler Jr.Taildraggers, Inc.taildraggersinc.com________________________________________________________________________________
Pietenpol-List: Re: skid ball
Original Posted By: "K5YAC"
Subject: Pietenpol-List: source for Cont. valve springs below- Fresno Air Parts,CA Steve-- Fresno Air Parts is one source for your valve springs. http://www.trade-a-plane.com/displaypdf ... 0000663775 fresnoairparts@att.netValve Spring Set, Complete (16 Ea. Springs) ........ 42.50Fresno AirpartsChandler Field520 West KearneyFresno, CA 93706USAPhone: 559-237-4863Fax: 559-237-2703________________________________________________________________________________Subject: Pietenpol-List: Re: skid ball
Subject: Pietenpol-List: source for Cont. valve springs below- Fresno Air Parts,CA Steve-- Fresno Air Parts is one source for your valve springs. http://www.trade-a-plane.com/displaypdf ... 0000663775 fresnoairparts@att.netValve Spring Set, Complete (16 Ea. Springs) ........ 42.50Fresno AirpartsChandler Field520 West KearneyFresno, CA 93706USAPhone: 559-237-4863Fax: 559-237-2703________________________________________________________________________________Subject: Pietenpol-List: Re: skid ball